1. Technical Field
The present invention relates to resin molded parts with a lock arm having a substantially plate shaped main body and a lock arm connected to a peripheral edge of the main body so as to protrude in the vertical direction of the main body, for instance, resin molded parts with lock arms used as movable guide members of a connector to which the movable guide member (parts called a “terminal deformation preventing member” or a “moving plate”) is attached to protect a protruding end of a male terminal in the inner part of a hood part of a female type connector in which the male terminal is accommodated until the female type connector is fitted to a male type connector and guide a connection to a female terminal thereto, a connector using the resin molded parts with the lock arm as the movable guide member and a method for forming the resin molded parts with the lock arm.
2. Description of the Related Art
Multi-polar connectors in which many small male terminals are incorporated include a connector to which a movable guide member (a moving plate) is attached to protect the protruding ends of the male terminals and guide a connection of mate female terminals in an inner part of a hood part for receiving a mate connector until the male terminals are fitted to the female terminals of the mate connector.
FIGS. 20 and 21 are explanatory views of this kind of a usual connector disclosed in, for instance, patent literature 1.
As shown in FIG. 20, this connector includes a male type connector 101, a female type connector 102 having a hood part 102A for receiving the male type connector 101 and a movable guide member 103 accommodated in the hood part 102A so as to slide in the moving direction of the male type connector 101 to protect and guide male terminals protruding in the hood part 102A from the female type connector 102.
The movable guide member 103 has a plate shaped main body part 104 in which through holes 105 corresponding to the number of male terminals are provided. At both ends in the longitudinal direction of the plate shaped main body part 104, lock arms 110 protrude that extend substantially vertically to the main body part 104. In the lock arms 110, slits 112 are formed that extend in the fitting direction of the connector. Thus, engaging parts 113 are ensured in the end parts of the lock arms 110.
As shown in FIG. 21(a), the engaging parts 113 of the ends of the lock arms 110 are fitted to parts between first protrusions 114 and second protrusions 115 provided in an inner wall of the hood part 102A so that the movable guide member 103 is temporarily engaged with the hood part.
On outer sidewalls of the male type connector 101, third protrusions 116 are provided that can be fitted in sliding to the slits 112 of the lock arms 110. When both the connectors 101 and 102 are fitted to each other, as shown in FIG. 21(b), the third protrusions 116 pass through inside the engaging parts 113 of the ends of the lock arms 110, and then, the male type connector 101 presses the movable member 103 in a direction shown by an arrow mark Y. Thus, as shown in FIG. 21(c), the temporary engagement of the engaging parts 113 and the second protrusions 115 is disengaged so that the movable member 103 may be pressed and moved to the direction shown by the arrow mark Y.
In this case, finally, after the engaging parts 113 pass the second protrusions 115, the lock arms 110 finish a role of the temporary engagement to be accommodated in spaces ensured in the rear parts of the second protrusions 115 and restored to original forms.
Further, when the fitted state of both the connectors 101 and 102 is released, as shown in FIG. 21(c), when the male type connector 101 is moved in the direction shown by an arrow mark Z, the third protrusions 116 of the male type connector 101 press the engaging parts 113 to go over the second protrusions 115. As shown in FIG. 21(d), under a state that the engaging arts 113 are located between the first protrusions 114 and the second protrusions 115, the third protrusions 116 of the male type connector 101 pass through inside the engaging parts 113 of the lock arms 110. Thus, the male type connector 101 is pulled out from the hood part 102A. However, since the engaging arts 113 of the lock arms 110 are held between the first protrusions 114 and the second protrusions 115, the movable guide member 103 is held in a temporarily engaged state at that position.
In the movable guide member 103 of the connector, the slits 112 of the above-described lock arms 110 are formed in rectangular holes passing through in the vertical directions (rightward and leftward) to the extending directions of the lock arms 110. Thus, a necessary accuracy of inner end faces of the engaging parts 113 of the ends of the lock arms 110 are ensured.
Patent literature 1: JP-A-4-209479
The slits 112 of the lock arms 110 in the above-described movable member 103 correspond to parts called undercuts in molding with a resin.
Ordinarily, when parts that includes a substantially plate shaped main body part and arm shaped protrusions formed on peripheral edges which protrude in the vertical direction of the main body part is molded with a resin, the parts is formed by opening and closing forward and backward a combination of a metal mold of a front surface side that forms the front surface side of the main body part and a metal mold of a rear surface side that forms the rear surface side.
However, when the arm shaped protrusions have undercut parts like the slits 112 passing through rightward and leftward as in the above-described lock arms 110, since the slits 112 as the undercut parts cannot be formed only by the metal mold of the front surface side and the metal mold of the rear surface side, a slide core moving rightward and leftward is ordinarily used as well as the metal mold of the front surface side and the metal mold of the rear surface side to form the slits.
However, when such a slide core is used, since the structure of the metal mold is complicated, the cost of a molded product is inconveniently high.